Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 35
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
BMC Plant Biol ; 24(1): 263, 2024 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-38594616

RESUMO

BACKGROUND: In agricultural production, fungal diseases significantly impact the yield and quality of cotton (Gossypium spp.) with Verticillium wilt posing a particularly severe threat. RESULTS: This study is focused on investigating the effectiveness of endophytic microbial communities present in the seeds of disease-resistant cotton genotypes in the control of cotton Verticillium wilt. The technique of 16S ribosomal RNA (16S rRNA) amplicon sequencing identified a significant enrichment of the Bacillus genus in the resistant genotype Xinluzao 78, which differed from the endophytic bacterial community structure in the susceptible genotype Xinluzao 63. Specific enriched strains were isolated and screened from the seeds of Xinluzao 78 to further explore the biological functions of seed endophytes. A synthetic microbial community (SynCom) was constructed using the broken-rod model, and seeds of the susceptible genotype Xinluzao 63 in this community that had been soaked with the SynCom were found to significantly control the occurrence of Verticillium wilt and regulate the growth of cotton plants. Antibiotic screening techniques were used to preliminarily identify the colonization of strains in the community. These techniques revealed that the strains can colonize plant tissues and occupy ecological niches in cotton tissues through a priority effect, which prevents infection by pathogens. CONCLUSION: This study highlights the key role of seed endophytes in driving plant disease defense and provides a theoretical basis for the future application of SynComs in agriculture.


Assuntos
Microbiota , Verticillium , Verticillium/fisiologia , Gossypium/genética , Gossypium/microbiologia , RNA Ribossômico 16S/genética , Bactérias/genética , Sementes/genética , Doenças das Plantas/microbiologia , Resistência à Doença/genética
2.
J Exp Bot ; 75(10): 3188-3200, 2024 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-38401150

RESUMO

The rhizotoxicity of protons (H+) in acidic soils is a fundamental constraint that results in serious yield losses. However, the mechanisms underlying H+-mediated inhibition of root growth are poorly understood. In this study, we revealed that H+-induced root growth inhibition in Arabidopsis depends considerably on excessive iron deposition in the root apoplast. Reducing such aberrant iron deposition by decreasing the iron supply or disrupting the ferroxidases LOW PHOSPHATE ROOT 1 (LPR) and LPR2 attenuates the inhibitory effect of H+ on primary root growth efficiently. Further analysis showed that excessive iron deposition triggers a burst of highly reactive oxygen species, consequently impairing normal root development. Our study uncovered a valuable strategy for improving the ability of plants to tolerate H+ toxicity by manipulating iron availability.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Ferro , Raízes de Plantas , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/metabolismo , Ferro/metabolismo , Arabidopsis/crescimento & desenvolvimento , Arabidopsis/metabolismo , Concentração de Íons de Hidrogênio , Proteínas de Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Espécies Reativas de Oxigênio/metabolismo
4.
Trends Plant Sci ; 28(8): 941-954, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37019715

RESUMO

Iron (Fe) is an essential micronutrient for plants, and its storage in the apoplast represents an important Fe pool. Plants have developed various strategies to reutilize this apoplastic Fe pool to adapt to Fe deficiency. In addition, growing evidence indicates that the dynamic changes in apoplastic Fe are critical for plant adaptation to other stresses, including ammonium stress, phosphate deficiency, and pathogen attack. In this review, we discuss and scrutinize the relevance of apoplastic Fe for plant behavior changes in response to stress cues. We mainly focus on the relevant components that modulate the actions and downstream events of apoplastic Fe in stress signaling networks.


Assuntos
Ferro , Plantas , Ferro/metabolismo , Plantas/metabolismo , Raízes de Plantas/metabolismo , Regulação da Expressão Gênica de Plantas
5.
Front Plant Sci ; 13: 958984, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36061760

RESUMO

The long-distance transport of iron (Fe) in the xylem is critical for maintaining systemic Fe homeostasis in plants. The loading form of Fe(II) into the xylem and the long-distance translocation form of Fe(III)-citrate have been identified, but how Fe(II) is oxidized to Fe(III) in the xylem remains unknown. Here, we showed that the cell wall-resided ferroxidases LPR1 and LPR2 (LPRs) were both specifically expressed in the vascular tissues of Arabidopsis thaliana, while disruption of both of them increased Fe(II) in the xylem sap and caused excessive Fe deposition in the xylem vessel wall under Fe-sufficient conditions. As a result, a large amount of Fe accumulated in both roots and shoots, hindering plant growth. Moreover, under low-Fe conditions, LPRs were preferentially induced in old leaves, but the loss of LPRs increased Fe deposition in the vasculature of older leaves and impeded Fe allocation to younger leaves. Therefore, disruption of both LPRs resulted in severer chlorosis in young leaves under Fe-deficient conditions. Taken together, the oxidation of Fe(II) to Fe(III) by LPRs in the cell wall of vasculature plays an important role in xylem Fe allocation, ensuring healthy Fe homeostasis for normal plant growth.

6.
Plant J ; 112(2): 549-564, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-36062335

RESUMO

Iron deficiency is a major constraint for plant growth in calcareous soils. The interplay between NO3 - and Fe nutrition affects plant performance under Fe-deficient conditions. However, how NO3 - negatively regulates Fe nutrition at the molecular level in plants remains elusive. Here, we showed that the key nitrate transporter NRT1.1 in Arabidopsis plants, especially in the shoots, was markedly downregulated at post-translational levels by Fe deficiency. However, loss of NRT1.1 function alleviated Fe deficiency chlorosis, suggesting that downregulation of NRT1.1 by Fe deficiency favors plant tolerance to Fe deficiency. Further analysis showed that although disruption of NRT1.1 did not alter Fe levels in both the shoots and roots, it improved the reutilization of apoplastic Fe in shoots but not in roots. In addition, disruption of NRT1.1 prevented Fe deficiency-induced apoplastic alkalization in shoots by inhibiting apoplastic H+ depletion via NO3 - uptake. In vitro analysis showed that reduced pH facilitates release of cell wall-bound Fe. Thus, foliar spray with an acidic buffer promoted the reutilization of Fe in the leaf apoplast to enhance plant tolerance to Fe deficiency, while the opposite was true for the foliar spray with a neutral buffer. Thus, downregulation of the shoot-part function of NRT1.1 prevents apoplastic alkalization to ensure the reutilization of apoplastic Fe under Fe-deficient conditions. Our findings may provide a basis for elucidating the link between N and Fe nutrition in plants and insight to scrutinize the relevance of shoot-expressed NRT1.1 to the plant response to stress.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Ferro/metabolismo , Arabidopsis/genética , Arabidopsis/metabolismo , Raízes de Plantas/metabolismo , Proteínas de Arabidopsis/metabolismo , Solo , Regulação da Expressão Gênica de Plantas , Nitratos/metabolismo , Proteínas de Plantas/metabolismo , Proteínas de Transporte de Ânions/genética
7.
Nat Commun ; 13(1): 561, 2022 01 28.
Artigo em Inglês | MEDLINE | ID: mdl-35091578

RESUMO

Plants use nitrate and ammonium as major nitrogen (N) sources, each affecting root development through different mechanisms. However, the exact signaling pathways involved in root development are poorly understood. Here, we show that, in Arabidopsis thaliana, either disruption of the cell wall-localized ferroxidase LPR2 or a decrease in iron supplementation efficiently alleviates the growth inhibition of primary roots in response to NH4+ as the N source. Further study revealed that, compared with nitrate, ammonium led to excess iron accumulation in the apoplast of phloem in an LPR2-dependent manner. Such an aberrant iron accumulation subsequently causes massive callose deposition in the phloem from a resulting burst of reactive oxygen species, which impairs the function of the phloem. Therefore, ammonium attenuates primary root development by insufficiently allocating sucrose to the growth zone. Our results link phloem iron to root morphology in response to environmental cues.


Assuntos
Compostos de Amônio/metabolismo , Arabidopsis/metabolismo , Ferro/metabolismo , Nitrogênio/metabolismo , Floema/metabolismo , Raízes de Plantas/metabolismo , Arabidopsis/genética , Arabidopsis/crescimento & desenvolvimento , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Parede Celular/genética , Parede Celular/metabolismo , Ceruloplasmina/genética , Ceruloplasmina/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Regulação da Expressão Gênica de Plantas , Glucanos/metabolismo , Mutação , Nitratos/metabolismo , Raízes de Plantas/genética , Raízes de Plantas/crescimento & desenvolvimento , Plantas Geneticamente Modificadas , Espécies Reativas de Oxigênio/metabolismo , Plântula/genética , Plântula/crescimento & desenvolvimento , Plântula/metabolismo
8.
Ophthalmic Genet ; 43(2): 240-247, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35014583

RESUMO

PURPOSE: To investigate the penetrance of MYOC gene mutation in primary open-angle glaucoma (POAG) through systematic review and meta-analysis. To explore the factors affecting the penetrance of MYOC and provide evidence-based medical evidence for clinical work. METHODS: We searched all studies that reported the penetrance of MYOC mutation in PubMed, Embase, Web of Science, and Chinese databases including Wanfang, CNKI (China National Knowledge Infrastructure), and CBM (China Bio-Med). Random effects meta-analysis was conducted to estimate the penetrance of MYOC mutation in POAG. RESULTS: Fifty-two studies were included in this analysis after screening. Meta-analysis of the penetrance of MYOC mutation showed that the penetrance of MYOC mutation in POAG was 60% (95% CI: 51.0% to 68.0%) and the penetrance of MYOC mutation in POAG and suspected POAG was 68% (95% CI: 60.0% to 75.0%). The penetrance of MYOC mutation increases with age. Among Caucasians, Asians, and Africans, the penetrance of MYOC mutation in POAG was 55%, 71%, 54%, respectively, and the penetrance of MYOC mutation in POAG and suspected POAG was 64%, 83%, and 57%, respectively. Besides, the penetrance of different MYOC mutation sites was significantly discrepant. The penetrance of MYOC mutation in POAG ranged from 10.3% to 100% depending on the mutation sites. Some MYOC mutation sites have a certain population specificity, which is only pathogenic in Caucasians or Asians. CONCLUSIONS: The penetrance of MYOC mutation in POAG showed significant differences due to different mutation sites. The penetrance increased with the accrescent of age. Ethnic difference was an important factor affecting the penetrance of MYOC mutation. Knowing the rules and influencing factors of the penetrance of MYOC mutations is significant for the assessment of the risk of POAG in carriers with the MYOC mutation.


Assuntos
Proteínas do Citoesqueleto/genética , Proteínas do Olho/genética , Glaucoma de Ângulo Aberto , Glicoproteínas/genética , Análise Mutacional de DNA , Glaucoma de Ângulo Aberto/diagnóstico , Humanos , Mutação , Penetrância
9.
Ann Palliat Med ; 10(8): 8701-8708, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34488359

RESUMO

BACKGROUND: There is a lack of data on drug-related problems (DRPs) occurring in nephrology department in China. The objective of this study was to identify and categorize the types and causes of DRPs and to assess their severity. DRPs were examined by clinical pharmacists and the results of their interventions were rated. METHODS: Clinical pharmacists reviewed all medication orders for patients and documented clinical pharmacy services within a nine-month study period. The Pharmaceutical Care Network Europe (PCNE) classification (Version 9.00) was used to identify DRPs. Our Primary outcomes measured the number, causes, types, potential hazards of DRPs and the types and success rate of intervention. RESULTS: Admission medication reconciliation data of 113 patients with chronic kidney disease (CKD) were collected and all of the medications were reviewed retrospectively. Exclude 26 patients who did not occurred DRPs, 87 patients (77%) identified 101 DRPs. The average DRP number per patient was 1.16. The most common type of problem was "treatment effectiveness P1" (84.16%; 85/101). The most common causes were "drug selection C1" (36.00%; 45/125), "dose selection C3" (29.60%; 37/125), and "patient related C7" (26.40%; 33/125). Clinical pharmacists totally proposed 249 interventions, of which 190 (76.31%) were fully accepted and implemented. CONCLUSIONS: DRPs are common among CKD patients in the nephrology department. Hence the necessity for pharmaceutical care to be improved to ensure the ongoing safety of patients.


Assuntos
Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Nefrologia , Preparações Farmacêuticas , Humanos , Farmacêuticos , Estudos Retrospectivos , Centros de Atenção Terciária
10.
Plant Cell ; 33(12): 3658-3674, 2021 12 03.
Artigo em Inglês | MEDLINE | ID: mdl-34524462

RESUMO

Protons (H+) in acidic soils arrest plant growth. However, the mechanisms by which plants optimize their biological processes to diminish the unfavorable effects of H+ stress remain largely unclear. Here, we showed that in the roots of Arabidopsis thaliana, the C2H2-type transcription factor STOP1 in the nucleus was enriched by low pH in a nitrate-independent manner, with the spatial expression pattern of NITRATE TRANSPORTER 1.1 (NRT1.1) established by low pH required the action of STOP1. Additionally, the nrt1.1 and stop1 mutants, as well as the nrt1.1 stop1 double mutant, had a similar hypersensitive phenotype to low pH, indicating that STOP1 and NRT1.1 function in the same pathway for H+ tolerance. Molecular assays revealed that STOP1 directly bound to the promoter of NRT1.1 to activate its transcription in response to low pH, thus upregulating its nitrate uptake. This action improved the nitrogen use efficiency (NUE) of plants and created a favorable rhizospheric pH for root growth by enhancing H+ depletion in the rhizosphere. Consequently, the constitutive expression of NRT1.1 in stop1 mutants abolished the hypersensitive phenotype to low pH. These results demonstrate that STOP1-NRT1.1 is a key module for plants to optimize NUE and ensure better plant growth in acidic media.


Assuntos
Proteínas de Transporte de Ânions/genética , Proteínas de Arabidopsis/genética , Arabidopsis/fisiologia , Nitratos/metabolismo , Proteínas de Plantas/genética , Rizosfera , Solo/química , Fatores de Transcrição/genética , Adaptação Fisiológica/genética , Proteínas de Transporte de Ânions/metabolismo , Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Transporte Biológico , Concentração de Íons de Hidrogênio , Proteínas de Plantas/metabolismo , Fatores de Transcrição/metabolismo
11.
Sci Total Environ ; 798: 149285, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34340090

RESUMO

Identifying the genes that affect cadmium (Cd) accumulation in plants is a prerequisite for minimizing dietary Cd uptake from contaminated edible parts of plants by genetic engineering. This study showed that Cd stress inhibited the expression of FERONIA (FER) gene in the roots of wild-type Arabidopsis. Knockout of FER in fer-4 mutants downregulated the Cd-induced expression of several genes related to iron (Fe) uptake, including IRT1, bHLH38, NRAMP1, NRAMP3, FRO2 andFIT. In addition, the Cd concentration in fer-4 mutant roots reduced to approximately half of that in the wild-type seedlings. As a result, the Cd tolerance of fer-4 was higher. Furthermore, increased Fe supplementation had little effect on the Cd tolerance of fer-4 mutants, but clearly improved the Cd tolerance of wild-type seedlings, showing that the alleviation of Cd toxicity by Fe depends on the action of FER. Taken together, the findings demonstrate that the knockout of FER might provide a strategy to reduce Cd contamination and improve the Cd tolerance in plants by regulating the pathways related to Fe uptake.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Cádmio/toxicidade , Ferro , Raízes de Plantas
12.
BMC Gastroenterol ; 21(1): 169, 2021 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-33849450

RESUMO

BACKGROUND: Surgical resection remains the best option for long-term survival in colorectal cancer (CRC); however, surgery can lead to tumor cell release into the circulation. Previous studies have also shown that surgery can affect cancer cell growth. The role of perioperative factors influencing long-term survival in patients presenting for CRC surgery remains to be investigated. METHODS: This retrospective single-center cohort study was conducted to collect the clinical data of patients who underwent elective laparoscopic resection for CRC from January 2014 to December 2015, namely clinical manifestations, pathological results, and perioperative characteristics. Survival was estimated using the Kaplan-Meier log-rank test. Univariable and multivariable Cox regression models were used to compare hazard ratios (HR) for death. RESULTS: A total of 234 patients were eligible for analysis. In the multivariable Cox model, tumor-node-metastasis (TNM) stage (stage IV: HR 30.63, 95% confidence interval (CI): 3.85-243.65; P = 0.001), lymphovascular invasion (yes: HR 2.07, 95% CI 1.09-3.92; P = 0.027), inhalational anesthesia with isoflurane (HR 1.96, 95% CI 1.19-3.21; P = 0.008), and Klintrup-Makinen (KM) inflammatory cell infiltration grade (low-grade inflammation: HR 2.03, 95% CI 1.20-3.43; P = 0.008) were independent risk factors affecting 5-year overall survival after laparoscopic resection for CRC. CONCLUSIONS: TNM stage, lymphovascular invasion, isoflurane, and KM grade were independent risk factors affecting CRC prognosis. Sevoflurane and high-grade inflammation may be associated with improved survival in CRC patients undergoing resection.


Assuntos
Neoplasias Colorretais , Estudos de Coortes , Neoplasias Colorretais/patologia , Neoplasias Colorretais/cirurgia , Humanos , Estadiamento de Neoplasias , Prognóstico , Estudos Retrospectivos , Fatores de Risco
13.
Commun Biol ; 4(1): 232, 2021 02 19.
Artigo em Inglês | MEDLINE | ID: mdl-33608634

RESUMO

Convincing evidence supports the premise that reducing α-synuclein levels may be an effective therapy for Parkinson's disease (PD); however, there has been lack of a clinically applicable α-synuclein reducing therapeutic strategy. This study was undertaken to develop a blood-brain barrier and plasma membrane-permeable α-synuclein knockdown peptide, Tat-ßsyn-degron, that may have therapeutic potential. The peptide effectively reduced the level of α-synuclein via proteasomal degradation both in cell cultures and in animals. Tat-ßsyn-degron decreased α-synuclein aggregates and microglial activation in an α-synuclein pre-formed fibril model of spreading synucleinopathy in transgenic mice overexpressing human A53T α-synuclein. Moreover, Tat-ßsyn-degron reduced α-synuclein levels and significantly decreased the parkinsonian toxin-induced neuronal damage and motor impairment in a mouse toxicity model of PD. These results show the promising efficacy of Tat-ßsyn-degron in two different animal models of PD and suggest its potential use as an effective PD therapeutic that directly targets the disease-causing process.


Assuntos
Antiparkinsonianos/farmacologia , Encéfalo/efeitos dos fármacos , Intoxicação por MPTP/tratamento farmacológico , Neurônios/efeitos dos fármacos , Doença de Parkinson/tratamento farmacológico , Peptídeos/farmacologia , alfa-Sinucleína/metabolismo , Animais , Comportamento Animal/efeitos dos fármacos , Encéfalo/metabolismo , Encéfalo/patologia , Encéfalo/fisiopatologia , Modelos Animais de Doenças , Regulação para Baixo , Células HEK293 , Humanos , Intoxicação por MPTP/genética , Intoxicação por MPTP/metabolismo , Intoxicação por MPTP/fisiopatologia , Masculino , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Atividade Motora/efeitos dos fármacos , Mutação , Neurônios/metabolismo , Neurônios/patologia , Doença de Parkinson/genética , Doença de Parkinson/metabolismo , Doença de Parkinson/fisiopatologia , Complexo de Endopeptidases do Proteassoma/metabolismo , Proteólise , Ratos Sprague-Dawley , alfa-Sinucleína/genética
14.
Biomed Pharmacother ; 133: 110937, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33217689

RESUMO

BACKGROUND: Compound sophorae decoction (CSD), a Chinese Herbal decoction, is frequently clinically prescribed for patients suffered from ulcerative colitis (UC) characterized by bloody diarrhea. Yet, the underlying mechanism about how this formulae works is remain elusive. METHODS: In the present study, the experimental colitis in C57BL/6 J mice was induced by oral administration of standard diets containing 3% dextran sodium sulfate (DSS), and CSD was given orally for treatment at the same time. The clinical symptoms including stool and body weight were recorded each day, and colon length and its histopathological changes were observed. Apoptosis of colonic epithelium was studied by detecting protein expression of cleaved caspase-3, and cell proliferation by Ki-67 immunohistochemistry. Tight junction complex like ZO-1 and occludin were also determined by transmission electron microscope and immunofluorescence. The concentration of FITC-dextran 4000 was measured to evaluate intestinal barrier permeability and possible signaling pathway was investigated. Mucin2 (MUC2) and notch pathway were tested through western blot. The M1/M2 ratio in spleen and mesenteric lymph nodes were detected by flow cytometry. And the mRNA levels of iNOS and Arg1 were examined by qRT-PCR. RESULTS: CSD could significantly alleviate the clinical manifestations and pathological damage. Body weight loss and DAI score of mice with colitis were improved and shortening of colon was inhibited. The administration of CSD was able to reduce apoptotic epithelial cells and facilitate epithelial cell regeneration. Increased intestinal permeability was reduced in DSS-induced colitis mice. In addition, CSD treatment obviously up-regulated the expression of ZO-1 and occludin and the secretion of MUC2, regulated notch signaling, and decreased the ratio of M1/M2. CONCLUSIONS: These data together suggest that CSD can effectively mitigate intestinal inflammation, promote phenotypic change in macrophage phenotype and enhance colonic mucosal barrier function by, at least in part, regulating notch signaling in mice affected by DSS-induced colitis.


Assuntos
Anti-Inflamatórios/farmacologia , Colite/tratamento farmacológico , Colo/efeitos dos fármacos , Medicamentos de Ervas Chinesas/farmacologia , Mucosa Intestinal/efeitos dos fármacos , Receptores Notch/metabolismo , Animais , Apoptose/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Colite/induzido quimicamente , Colite/metabolismo , Colite/patologia , Colo/metabolismo , Colo/patologia , Citocinas/metabolismo , Sulfato de Dextrana , Modelos Animais de Doenças , Mucosa Intestinal/metabolismo , Mucosa Intestinal/patologia , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Masculino , Camundongos Endogâmicos C57BL , Mucina-2/metabolismo , Ocludina/metabolismo , Permeabilidade , Regeneração/efeitos dos fármacos , Transdução de Sinais , Junções Íntimas/efeitos dos fármacos , Junções Íntimas/metabolismo , Junções Íntimas/patologia , Proteína da Zônula de Oclusão-1/metabolismo
15.
Plant Physiol ; 184(4): 1900-1916, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33093234

RESUMO

K+ and NO3 - are the major forms of potassium and nitrogen that are absorbed by the roots of most terrestrial plants. In this study, we observed that a close relationship between NO3 - and K+ in Arabidopsis (Arabidopsis thaliana) is mediated by NITRATE TRANSPORTER1.1 (NRT1.1). The nrt1.1 knockout mutants showed disturbed K+ uptake and root-to-shoot allocation, and were characterized by growth arrest under K+-limiting conditions. The K+ uptake and root-to-shoot allocation of these mutants were partially recovered by expressing NRT1.1 in the root epidermis-cortex and central vasculature using SULFATE TRANSPORTER1;2 and PHOSPHATE1 promoters, respectively. Two-way analysis of variance based on the K+ contents in nrt1.1-1/K + transporter1, nrt1.1-1/high-affinity K + transporter5-3, nrt1.1-1/K + uptake permease7, and nrt1.1-1/stelar K + outward rectifier-2 double mutants and the corresponding single mutants and wild-type plants revealed physiological interactions between NRT1.1 and K+ channels/transporters located in the root epidermis-cortex and central vasculature. Further study revealed that these K+ uptake-related interactions are dependent on an H+-consuming mechanism associated with the H+/NO3 - symport mediated by NRT1.1. Collectively, these data indicate that patterns of NRT1.1 expression in the root epidermis-cortex and central vasculature are coordinated with K+ channels/transporters to improve K+ uptake and root-to-shoot allocation, respectively, which in turn ensures better growth under K+-limiting conditions.


Assuntos
Proteínas de Transporte de Ânions/genética , Proteínas de Transporte de Ânions/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Arabidopsis/crescimento & desenvolvimento , Transporte Biológico/fisiologia , Nitratos/metabolismo , Deficiência de Potássio/metabolismo , Arabidopsis/genética , Transporte Biológico/genética , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Variação Genética , Genótipo , Mutação , Raízes de Plantas/metabolismo , Brotos de Planta/metabolismo , Deficiência de Potássio/genética
16.
Sci Total Environ ; 746: 141244, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32768787

RESUMO

Global climate change has exacerbated flooding in coastal areas affected by soil salinization. Ammonium (NH4+) is the predominant form of nitrogen in flooded soils, but the role played by NH4+ in the plant response to salt stress has not been fully clarified. We investigated the responses of Arabidopsis thaliana, Oryza sativa, and Nicotiana benthamiana plants fed with NH4+. All species were hypersensitive to NaCl stress and accumulated more Cl- and less Na+ than those fed with NO3-. Further investigation of A. thaliana indicated that salt hypersensitivity induced by the presence of NH4+ was abolished by removing the Cl- but was not affected by the removal of Na+, suggesting that excess accumulation of Cl- rather than Na+ is involved in NH4+-conferred salt hypersensitivity. The expression of nitrate transporter NRT1.1 protein was also up-regulated by NH4+ treatment, which increased root Cl- uptake due to the Cl- uptake activity of NRT1.1 and the absence of uptake competition from NO3-. Knockout of NRT1.1 in plants decreased their root Cl- uptake and retracted the NH4+-conferred salt hypersensitivity. Our findings revealed that NH4+-aggravated salt stress in plants is associated with Cl- over-accumulation through the up-regulation of NRT1.1-mediated Cl- uptake. These findings suggest the significant impact of Cl- toxicity in flooded coastal areas, an issue of ecological significance.


Assuntos
Compostos de Amônio , Nitratos/toxicidade , Nitrogênio , Raízes de Plantas , Estresse Salino
17.
Biomed Pharmacother ; 130: 110537, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32717630

RESUMO

Rhizoma Bletillae, the tubes of Bletilla striata, has been traditionally used in China as a hemostatic agent. In preliminary studies, the major active fraction responsible for its hemostatic effect have been confirmed to be Rhizoma Bletillae polysaccharide (RBp), but the hemostatic mechanism of action of RBp is still unknown.The main aim of this study was to clarify its mechanism of hemostatic effect. RBp was prepared by 80 % ethanol precipitation of the water extract of Rhizoma Bletillae followed by the Sevag method to remove proteins. The average molecular weight (Mw) of the crude RBp maintained at a range of 30.06-200 KDa. The hemostatic effects of RBp were evaluated by testing its effect on the platelet aggregation of rat platelet-rich plasma (PRP). PRP was dealt with different concentrations of RBp and platelet aggregation was measured by the turbidimetric method. The hemostatic mechanism of RBp was investigated by examining its effect on platelet shape, platelet secretion, and activation of related receptors (P2Y1, P2Y12 and TXA2) by electron microscopy and the turbidimetric method. RBp significantly enhanced the platelet aggregations at concentrations of 50-200 mg/L in a concentration-dependent manner. The inhibitory rate of platelet aggregation was significantly increased by apyrase and Ro31-8220 in a concentration-dependent manner, while RBp-induced platelet aggregation was completely inhibited by P2Y1, P2Y12 and the PKC receptor antagonists. However, the aggregation was not sensitive to TXA2. RBp, the active ingredients of Rhizoma Bletillae responsible for its hemostatic effect, could significantly accelerate the platelet aggregation and shape change. The hemostatic mechanism may involve activation of the P2Y1, P2Y12, and PKC receptors in the adenosine diphosphate (ADP) receptor signaling pathway.


Assuntos
Hemostáticos/farmacologia , Plasma Rico em Plaquetas/efeitos dos fármacos , Polissacarídeos/farmacologia , Receptores Purinérgicos P2/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Animais , Relação Dose-Resposta a Droga , Técnicas In Vitro , Peso Molecular , Extratos Vegetais/farmacologia , Tubérculos/química , Agregação Plaquetária/efeitos dos fármacos , Proteína Quinase C/efeitos dos fármacos , Ratos , Receptores Purinérgicos P2Y1/efeitos dos fármacos , Receptores Purinérgicos P2Y12/efeitos dos fármacos
18.
Breastfeed Med ; 15(7): 471-474, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32412775

RESUMO

Background and Objective: We investigated whether (1) there are any differences in lactational breast abscesses between patients from whom methicillin-resistant Staphylococcus aureus (MRSA) and those from whom methicillin-sensitive S. aureus (MSSA) were isolated from pus samples and (2) there are differences in the effects of ultrasound-guided aspiration. Materials and Methods: The clinical data of 171 patients with lactational breast abscesses treated by ultrasound-guided aspiration in Beijing from January to July 2018 were retrospectively analyzed. The patients were divided into MSSA infection (N = 132) and MRSA infection (N = 39) groups according to their bacterial culture results. Abscess cavity location, abscess cavity number, maximum abscess cavity size, antibiotic utilization rate, and cure rate were compared between the groups. Cure rate refers to the proportion of the total number of cases remaining after the elimination of failed cases. The number of ultrasound-guided aspiration procedures performed for healing between the two groups was also compared. Results: There were no significant differences in abscess cavity location, abscess cavity amount, and abscess cavity size between both groups. The antibiotic utilization rate of the two groups were 58.3% (MSSA, 77/132) and 69.2% (MRSA, 27/39), respectively, and there were no significant differences between both groups. The cure rates of ultrasound-guided aspiration of the two groups were 97.7% (MSSA, 129/132) and 92.3% (MRSA, 36/39), and there were no significant differences between both groups. There were also no significant differences in the median number of aspiration performed for cure between the MRSA infection group (median = 3, range = 1-10) and the MSSA infection group (median = 3, range = 1-14). Conclusion: Lactational breast abscesses are the same irrespective of the type of S. aureus infection. Treatment by ultrasound-guided aspiration for patients with MRSA infection can achieve the same effect as that for those with MSSA infection.


Assuntos
Abscesso/tratamento farmacológico , Doenças Mamárias/terapia , Drenagem/métodos , Mastite/terapia , Infecções Estafilocócicas/terapia , Staphylococcus aureus/isolamento & purificação , Abscesso/diagnóstico por imagem , Abscesso/microbiologia , Adulto , Pequim , Doenças Mamárias/etiologia , Aleitamento Materno , Feminino , Humanos , Mastite/microbiologia , Staphylococcus aureus Resistente à Meticilina , Estudos Retrospectivos , Infecções Estafilocócicas/diagnóstico por imagem , Resultado do Tratamento , Ultrassonografia de Intervenção
19.
Plant Cell Environ ; 43(1): 275-291, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31703150

RESUMO

Although the alteration of DNA methylation due to abiotic stresses, such as exposure to the toxic metal cadmium (Cd), has been often observed in plants, little is known about whether such epigenetic changes are linked to the ability of plants to adapt to stress. Herein, we report a close linkage between DNA methylation and the adaptational responses in Arabidopsis plants under Cd stress. Exposure to Cd significantly inhibited the expression of three DNA demethylase genes ROS1/DML2/DML3 (RDD) and elevated DNA methylation at the genome-wide level in Col-0 roots. Furthermore, the profile of DNA methylation in Cd-exposed Col-0 roots was similar to that in the roots of rdd triple mutants, which lack RDD, indicating that Cd-induced DNA methylation is associated with the inhibition of RDD. Interestingly, the elevation in DNA methylation in rdd conferred a higher tolerance against Cd stress and improved cellular Fe nutrition in the root tissues. In addition, lowering the Fe supply abolished improved Cd tolerance due to the lack of RDD in rdd. Together, these data suggest that the inhibition of RDD-mediated DNA demethylation in the roots by Cd would in turn enhance plant tolerance to Cd stress by improving Fe nutrition through a feedback mechanism.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/genética , Arabidopsis/metabolismo , Cádmio/toxicidade , Desmetilação do DNA , Tolerância a Medicamentos/fisiologia , Ferro/metabolismo , Adaptação Fisiológica , Arabidopsis/efeitos dos fármacos , Proteínas de Arabidopsis/genética , Cádmio/metabolismo , DNA Glicosilases/metabolismo , Metilação de DNA , Elementos de DNA Transponíveis , Tolerância a Medicamentos/genética , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Genes de Plantas , Mutação , Proteínas Nucleares/metabolismo , Raízes de Plantas/metabolismo , Estresse Fisiológico
20.
J Gastroenterol Hepatol ; 32(12): 1966-1974, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28370348

RESUMO

BACKGROUND AND AIM: Epithelial-mesenchymal transition (EMT), characterized by the decrease of E-cadherin (E-Cad) and increase in vimentin and alpha-smooth muscle actin (α-SMA), was demonstrated to participate in inflammatory bowel disease-related fibrosis. miR-200b plays an anti-fibrosis role in inhibiting EMT by targeting ZEB1 and ZEB2. But the stability of exogenous miR-200b in blood limits its application. Microvesicles (MVs), which can transfer miRNAs among cells and prevent them from degradation, may provide an excellent transport system for the delivery of miR-200b in the treatment of fibrosis. METHODS: Bone marrow mesenchymal stem cells (BMSCs) were transfected with lentivirus to overexpress miR-200b. The MVs packaged with miRNA-200b were harvested for the anti-fibrotic treatment using in vitro (transforming growth factor beta 1-mediated EMT in intestinal epithelial cells: IEC-6) and in vivo (TNBS-induced intestinal fibrosis in rats) models. The pathological morphology was observed, and the fibrosis related proteins, such as E-Cad, vimentin, α-SMA, ZEB1, and ZEB2, were detected. RESULTS: MiR-200b-MVs would significantly reverse the morphology in TGF-ß1-treated IEC-6 cells and improve the TNBS-induced colon fibrosis histologically. The treatment of miR-200b-MVs increased miR-200b levels both in the IEC-6 cells and colon, resulting in a significant prevention EMT and alleviation of fibrosis. The expression of E-Cad was increased, and the expressions of vimentin and α-SMA were decreased. ZBE1 and ZEB2, the targets of miR-200b, were also decreased. CONCLUSIONS: miR-200b could be transferred from genetically modified BMSCs to the target cells or tissue by MVs. The mechanisms of miR-200b-MVs in inhibiting colonic fibrosis were related to suppressing the development of EMT by targeting ZEB1and ZEB2.


Assuntos
Micropartículas Derivadas de Células , Colite/tratamento farmacológico , Colite/fisiopatologia , Transição Epitelial-Mesenquimal/efeitos dos fármacos , Intestinos/patologia , MicroRNAs/administração & dosagem , MicroRNAs/fisiologia , Actinas/metabolismo , Animais , Caderinas/metabolismo , Células Cultivadas , Colite/patologia , Modelos Animais de Doenças , Sistemas de Liberação de Medicamentos , Transição Epitelial-Mesenquimal/genética , Fibrose , Proteínas de Homeodomínio , Mucosa Intestinal/metabolismo , Masculino , MicroRNAs/metabolismo , MicroRNAs/farmacologia , Terapia de Alvo Molecular , Ratos Sprague-Dawley , Fatores de Transcrição , Vimentina/metabolismo , Homeobox 1 de Ligação a E-box em Dedo de Zinco
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...